<template>
    <div class="list" ref="wrapper">
        <div>
            <div class="area">
                <div class="title border-topbottom">当前城市</div>
                <div class="button-list">
                    <div class="button-wrapper">
                        <div class="button">{{this.city}}</div>
                    </div>
                </div>
            </div>
            <div class="area">
                <div class="title border-topbottom">热门城市</div>
                <div class="button-list">
                    <div class="button-wrapper" v-for="item of hotCities" :key="item.id" @click="handleCityClick(item.name)">
                        <div class="button">{{item.name}}</div>
                    </div>
                </div>
            </div>
            <div class="area" v-for="(item,key) of cities" :key="key" :ref="key">
                <div class="title border-topbottom">{{key}}</div>
                <div class="item-list" v-for="innerItem of item" :key="innerItem.id" @click="handleCityClick(innerItem.name)">
                    <div class="item border-bottom">{{innerItem.name}}</div>
                </div>
            </div>
        </div>
    </div>
</template>

<script>
import BScroll from "better-scroll"
import { mapState,mapMutations } from 'vuex'
export default {
    name: 'CityList',
    props: {
        hotCities: Array,
        cities: Object,
        letter: String
    },
    computed: {
	  ...mapState(['city'])
    },
    mounted () {
        this.scroll = new BScroll(this.$refs.wrapper)
    },
    watch: {//侦听器
        letter () {//letter是传递进来的数据，对他进行侦听
            if(this.letter){//如果数据不为空
                const element=this.$refs[this.letter][0]//为列表循环每一项绑定一个ref,因为这个ref是循环绑定的,所以是个数组,要加上[0]才是一个DOM元素
                this.scroll.scrollToElement(element)//better-scroll自带的api,作用是选择展示（滚动到）哪一个地方,参数element必须是个dom元素
            }
        }
    },
    methods: {
        handleCityClick (city) {
            //this.$store.dispatch('changeCity',city)
            this.changeCity(city)
            this.$router.push('/')
        },
        ...mapMutations(['changeCity'])//把mutations中的changeCity映射到这个组件的一个名叫changeCity的方法中
    }
}
</script>

<style lang="stylus" scoped>
    @import '~@/assets/styles/varibles.styl'
    .border-topbottom
        &:before
            border-color: #ccc
        &:after
            border-color: #ccc
    .border-bottom
        &:before
            border-color: #ccc
    .list
        position: absolute
        overflow: hidden
        left: 0
        top: 1.58rem
        right: 0
        bottom: 0
        .title
            line-height: .54rem
            background: #eee
            color: #666
            padding-left: .2rem
            font-size: .26rem
        .button-list
            overflow: hidden
            padding: .1rem .6rem .1rem .1rem
            .button-wrapper
                float: left
                width: 33.33%
                .button
                    margin: .1rem
                    padding: .1rem 0
                    text-align: center
                    border: .02rem solid #ccc
                    border-radius: .1rem
        .item-list
            .item
                line-height: .76rem
                padding-left: .2rem
</style>
